Drier for composite paper and veneer sheet material



Jan. 7, 1958 c. A. BURKHOLDER 2,318,660

DRIER FOR COMPOSITE PAPER muvmm 'SHEET MATERIAL Filed Aug. 24, 1954 Y 3 Sheets-Sheet 1 IN V EN TOR. C f7. .Bazkbolder M mi;

HTTXS 1958 c. A. BURKHOLDER 2,318,660

DRIER FOR COMPOSITE PAPER AND VENEER SHEET MATERIAL Filed Aug, 24, 1954 3 Sheets-Sheet 2 v INVENTOR. C, H .B,uTk oZa e1 HTTYS Jan. 7, 1958 c. A. BURKHOLDER DRIER FOR COMPOSITE PAPER- AND VENEER SHEET MATERIAL Filed Aug. 24, 1954 3 Sheets-Sheet 3 INVENTOR. C H. Burkkolder HTTYS United States Patent This invention is directed to' apparatus for use in the continuous-run manufacture of composite paper and wood veneer sheet material; the? invention relating to, and it Being a primary object to provide, a novel kiln adapted for use in connection with the manufacture of such sheet material by the method contemplated in my copending application for United States Letters" Patent, Serial No. 443,793, filed July 16, I954, now abandoned.

In the course of the continuous-run manufacture of composite paper and wood veneer sheet material in accordance with such method, a longitudinal row of wood veneer sectionscomprising an inter'n'iediate lamination is initially engaged and adhesively bonded between outer lamination's in the term of runs of heavy-duty pa er, such as Kraffl Such i'nitial formation of the sheet material is accomplished in a laminatin mechanism from which the sheet material feeds in a continuous run; it being desirable that such sheet material, beyond the laminating mechanism, be subjected simultaneously to conditions of heat and compression for the purpo e of accelerating and completing the bond, as well as drying said material prior to subsequent steps in the method, such as edge trimming and transverse cutting into separate lengths or' panels.

It is therefore an important object of this invention to provide a novel kiln, through which the sheet material continuously travels, for the purpose of subjecting said material to such conditions of heat and compression, simultaneons'ly'.

Another object of the invention is to provide a novel kiln, as above, which includes cooperating. longitudinal runs of endless conveyors, which conveyors are of foraminous, heavy-duty, screen-like material, and between the runs of which conveyors the composite aper and wood veneer sheet material is engaged, traveling with said runs for the full length of the kiln.

A further object of the instant invention is to provide a kiln, as in the preceding para-graph, wherein the fora-minou's' cooperating of the endless conveyorswhich runs extend. longitudinally one over the otherare engaged at spaced points between cooperating upper and lower pressure rolls; such rolls urging the runs of the conveyors toward eachother, whereby to maintain the sheet material intermediate said runs under compression.

A still further obj'ect of the invention is to provide a kiln, as above described, which includes novel means to maintain a heated, constantly circulating air flow against the foraminous runs of the endless conveyors, and the sheet material engaged between and traveling with said runs; this to the end that such material is subjected to the desired condition. of heat simultaneously with the application of compression on said material.

It is" also an object ot the invention to provide a kiln, for the purpose described, which functions positively, smoothly, and effectively, and one which is capable of accomplishing the treatment of the sheet materia-l, under conditions of heat and compression, with the apparatus running at a substantial speed.

Still another object of the invention is to provide a practical, reliable, and durable kiln, and one which will be exceedingly effective for the purpose for which it 18 designed.

These objects are accomplished by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawings:

Fig. 1 is a side elevation, mostly diagrammatic and foreshortened, of the kiln; the sheet material laminating mechanism being shown in part at the" rear end of the kiln, while the edge trimming disc assembly is shown at the opposite end thereof.

Fig. 2 is an enlarged fragmentary perspective view, foreshortened, showing diagrammatically and in progressionthe feeding of the tow of wood veneer sections to the nip rolls of the laminating mechanism, the initial lamination beyond said rolls of the row between the runs of paper, and thereb'eyond the initial engagement of the laminated sheet material between the cooperating foramin'ous runs of the conveyor in the Fig. 3 is an enlarged transverse sectional elevation on line 3=--3 of Fig. 1; the view includingdiagrammaticallythe related air heater and blower unit.

Fig. 4 is an enlarged fragmentary longitudinal sectional elevation of the kiln; the runs of the endless foraminous conveyors being omitted, in. the main, for the sake of clarity.

Fig. 5 is an enlarged fragmentary longitudinal sectional elevation showing, a pair of the pressure rolls and the cooperating foraminous run's therebetween, with the sheet material engaged between said runs.

Fig. 6 is an enlarged fragmentaryend elevation showing the mounting of a related pair of said pressure rolls.

Referring now more particularly to the drawings and to the characters of reference marked thereon, the kiln, which is the subject of this invention, is indicated. generally at 1. Such kiln, while being quite long in practice, is in the present disclosure shown considerably foreshortened.

The kiln 1 is disposed adjacent, but extends longitudinally beyond, the sheet material laminating mechanism, indicated generally at 2.- In such sheet material laminating mechanism an upper run 3 and a lower run 4 of heavy-duty paper, fed from a suitable source (not shown), are carried downwardly and upwardly, respectively, over u-p'per direction-changing rolls 5 and lower directionchanging rolls 6 in said mechanism 2.

During the course of the travel of the upper run 3 and lower run 4 of paper in the laminating mechanism 2, such runs have an adhesive applied to the proper face thereof. This is accomplishedby transfer rolls 7 and 8 running, at the bottom, in adhesive troughs 9 and 1'0, and running adjacent the top in engagement with certain' ones of the upper direction-'changing'rolls 5' and lower direction-changing rolls 6, respectively;

After the adhesive is applied to the runs 3 and 4 of paper, such runs extend to', and turn about, horizontal, transversely extending nip rolls 11 in the laminating mechanism 2, and to which nip rolls a longitudinal row 12 of transversely extending wood veneer sections 13 is continuously fed, as at 14, by a transfer conveyor (not shown), which is described in detail in my copending application for United States Letters Patent, Serial No. 450,153, filed August 16, 1954.

As the runs 3 and 4 of paper, together with the row 12 of wood veneer sections 13, constantly feed between the nip rolls 11,- there is an initial lamination of such elements whereby to form the composite paper. and wood veneer sheet material, indicated generally at 15 Forwardly of the nip rolls 11 the sheet material 15 runs between cooperating upper and lower pressure and feed rolls; the upper rolls being indicated at 16 and the lower rolls at 17.

The rolls 16 and 17 not only impart pressure on the sheet material 15 from above and below, but also constantly feed said material in an advancing direction at a constant speed; said rolls being driven by an endless chain and sprocket unit 18 from a cross shaft 19 actuated in turn by an endless chain and sprocket unit 20 from a gear box 21.

The gear box 21 is driven from a longitudinal shaft 22 which extends alongside the kiln 1, and which shaft derives its power from another gear box 23 actuated by an endless unit 24 from a counter-shaft 25 journaled in connection with a suitable frame forwardly of the kiln 1; said counter-shaft being driven from an electric motor unit 26 by an endless chain and sprocket unit 27.

Certain working parts of the kiln 1 are also driven from the counter-shaft 25 in themanner as will hereinafter appear.

From the pressure and feed rolls 16 and 17 of the laminating mechanism 2, the composite paper and wood veneer sheet material 15 feeds into the kiln 1, traveling in such kiln for the full length thereof; said kiln being constructed and functioning as follows:

The kiln 1 comprises a longitudinally extending, elongated housing 28, such housing including a top 29, a bottom 30, and sides 31 and 32all being wall-insulated as shown.

An open or skeleton, longitudinal mounting frame, indicated generally at 33, and which is rectangular in cross section, extend-s through the housing 1 from end to end thereof, with some extension beyond each end of the kiln; such mounting frame being supported some distance above the bottom 30 of housing 28 by legs 34. The mounting frame 33 is of such cross-sectional size that when it is supported in the housing 28 by the legs 34, clearance exists between said frame and said housing, as shown.

Upper and lower flexible endless conveyors 35 and 36 extend longitudinally through the housing 28, with the adjacent longitudinal runs 37 and 38, respectively, initially in engagement.

The endless conveyors 35 and 36' are metallic and of foraminous or screen-like form, but of heavy-duty construction. Said conveyors 35 and 36 are carried, at the rear end, on upper and lower end rolls 39 and 40, respectively. At their forward ends the conveyors 35 and 36 are carried on end rolls 41 and 42, respectively.

The rolls 39 and 40, as well as the rolls 41 and 42, are

journaled in connection with end extensions of the'mounting frame 33 outside of the housing 28; said housing having end walls, one of which is indicated at 43, through which the conveyors 35 and 36 pass in the course of their travel. The rear end rolls 39'and 40 are enclosed within a'housing extension 44.

Within the housing 28 the cooperating runs 37 and 38 pass, at longitudinally :spacedpoints, between pairs of vertically alined pressure rolls; the upper pressure rolls being indicated at 45 and the lower pressure rolls at 46.

Longitudinal side beams 47 are included in the mounting frame 33, and the lowerpressure rolls 46 are carried on lower cross shafts 48 journaled, as at 49, on said side beams.

The upper pressure rolls 45 are carried on cross shafts 50 whose journals 51 are mounted in connection with longitudinally extending arms 52 extending atop the side beams 47. At one end each of the arms 52 is vertically swingably pivoted, as at 53, to the related side beam, while at the opposite end each arm is fitted with an adjustment screw 54 which limits the extent of downward swinging of the arm. With this arrangement each upper pressure roll 45 normally exerts a forceful downward pressure toward the related lower pressure roll 46, whereby to effectively subject the cooperating runs 37 and 38 to compression; the extent of which compression is controlled by adjustment of the screws '54.

The longitudinal housing 28 is divided into separate compartments by at least one intermediate partition 55 through which the conveyors 35 and 36 pass, and each such compartment has a constant circulation or flow of heated air maintained therein in the following manner:

There is provided--at a point spaced from the housing 28-an air heater and blower unit, indicated generally at 56; such unit delivering, in substantial volume, a constant flow of heated air through a primary feed duct 57 which leads to a transition 58.

A lower duct 59 feeds the heated air from the transition 58 into the rear end of each compartment of the housing 28 at a relatively low inlet 60, while a separate duct 61 feeds the heated air from the transition 58 to an upper inlet 62.

The heated air as thus fed in substantial volume and under some pressure into each compartment of the longitudinal housing 28, is delivered against the runs 37 and 38 in the following manner:

The upper run 63 and the lower run 64 of the endless conveyors 35 and 36 are carried on guide rails, indicated at 65 and 66; said guide rails being fixed in connection with the mounting frame 33.

Longitudinal upper bafile plates 67 extend within the housing 28 between the upper corners thereof and the guide rails 65, thus forming an upper passage 68 with which each upper inlet 62 communicates, and from which upper passage the heated air may only circulate downwardly through the upper run 63.

Similarly, longitudinal lower bafile plates 69 connect between the sides 31 and 32 of the housing 28 and corresponding ones of the lower guide rails 66 whereby to form a lower passage 70 with which each inlet 60 communicates, and from which lower passage 70 the heated air may only circulate upwardly through the lower run 64.

The upper pressure rolls 45 and lower pressure rolls 46, except the rear pair which lies within the housing extension 44, are each encompassed by a hood 71 fixed in connection with the mounting frame 33; such hoods definingtherebetweenvertical air flow passages 72 which lead from the upper passage 68 and lower passage 70 to the cooperating runs 37 and 38 of the endless conveyors 35 and 36. Such air flow passages 72 are closed at the sides by slightly downwardly converging closure plates 72a; the hoods 71 and closure plates 72a terminating at the adjacent edges close to but spaced from the cooperating runs 37 and 38.

The sides 31 and 32 are formed, intermediate the top and bottom, with laterally projecting, longitudinally extending exhaust troughs 73 and 74 which open into said housing.

Adjacent the forward end of each compartment of the longitudinal housing 28 there are exhaust ducts 75 and 76 which communicate with the air troughs 73 and 74 at the tip thereof; such ducts leading to a common, central longitudinal exhaust duct 77 which communicates with an electric motor exhaust fan 78 which discharges into an exhaust stack 79.

The endless conveyors 35 and 36 are driven from the upper and lower end rolls 41 and 42, which rolls are carried on cross shafts 80 and 81, respectively. Such cross shafts 80 and 81 are inter-connected by an endless chain and sprocket unit 82, while the lower cross shaft 81 is driven from the counter-shaft 25 by an endless chain and sprocket unit'83; the direction of drive being such that the runs 37 "and 38 travel forwardly or advance, and at exactly the same speed.

The endless'conveyors 35 and 36 are maintained under proper tension by counter-weighted belt tighteners 84 and 85 which cooperate with said endless conveyors adjacent the end rolls 41 and 42.

In operation of the above described kiln, the composite paper and wood veneer sheet material 15 is delivered, from the pressure and feed rolls 16 and 17 of the laminating mechanism 2, between the foraminous runs 37 and 38 of the endless conveyors 35 and 56, respectively; the sheet material as frictionally engaged'between said runs being advanced therewith through the kiln 1.

In such kiln 1 the sheet material between the runs 37 and 38 is maintained under substantial. compression; this by reason of the action of the pairs of upper and lower pressure rolls 45 and 46 on said runs. This compression imposes a positive andeffective bondingv action on the sheet material 15; i. e.,. aids in accomplishing a fulland effective adhesive bond between the runs 3 and 4 of paper which comprise the outer laminations, and the row 12 of wood veneer sections 13 which comprises the intermediate lamination.

Additionally, the heated air which is constantlymaintained in circulation against theforaminous runs 37 and 38, as well as the sheet material 15 therebetween, acts also to aid in the bonding of the laminations and the drying. of the sheet material before it is discharged from. the kiln. Drying of the sheet material is important not only from the standpoint of aiding in the bonding of the laminations, but to reduce the moisture content of said sheet material to a point such that warping or de-lamination is prevented in the finished product.

The circulation of heated air within the kiln 1, with' the air flowing into direct contact with theruns 37 and 38, and the sheet material 15, is assured by the flow control structure within said" kiln. The heated air from the upper passage 68 and lower passage 70 is directed by the assembly of baflie plates 67, baffle plates 69, hoods 71, and side closure plates 72a in streams which directly impinge on said runs and sheet material; the heated air, after such impingement, escaping between the inner edges of said parts and the runs into side portions of the housing 28 separate from passages 68 and 70, and particularly into the air exhaust troughs 73 and 74. From such air exhaust troughs 73 and 74 the air, which is moisture laden, is withdrawn through the ducts 75 and 76 into the common duct 74 and thence exhausted through the stack 79; all by means of the electric motor driven exhaust fan 78.

After the sheet material 15 has passed through the kiln and is delivered from the endless conveyors 35 and 36 at the forward end, such material is trimmed by cooperating upper and lower, power driven edge trimming discs, shown generally at 86; the uppermost discs being on a common cross shaft actuated by an endless chain and sprocket unit 87, while the lowermost discs are on a common cross shaft actuated by an endless chain and sprocket unit 88. I

In the manufacture of the sheet material 15 for certain purposes, it is desirable that the wood veneer sections 13, which comprise the row 12 be arranged with predetermined adjacent ones of said sections in edge to edge engagement and other adjacent ones of said sections spaced apart. The present apparatus is shown as in use with sheet material thus formed; i. e., with the intermediate lamination having spacing between predetermined adjacent ones of the wood veneer sections 13.

As the sheet material passes through the apparatus, particularly in the kiln 1, the compression is such that the upper and lower runs 3 and 4 of paper are directly bonded together as a web 89 which spans the gap between the spaced wood veneer sections.

As the upper pressure rolls 45 are capable of vertical floating motion, they are especially effective in connection with the accomplishment of the desirable bonding of the runs of paper in the webs 89; it being recognized that such bonding initially occurs to some extent upon passage of the sheet material between the pressure and feed rolls 16' and 17.

With the described kiln, freshly adhesively laminated, composite paper and wood veneer sheet material is eifectively and positively bonded, under controlled conditions of compression and heat, yet with the sheet material traveling at substantial speed through the kiln in the course of the continuous-run manufacture of said material; the material-=as fed. from the kiln-being fiat, and dry.

From the foregoing description it will be readily seen that there has been produced such a device as will substantially fulfill the objects of the invention, as set forth herein.

While this specification sets forth the present and preferred construction of the device, still in practice such deviations therefrom may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described the invention, the following. is claimed as new and useful, and upon which Letters Patent are desired:

l. A kiln for preformed, continuously traveling,- composite paper and wood veneer sheet material having freshly adhesively engaged laminations, comprising a housing, an open longitudinal frame mounted in the housing, a longitudinal driven conveyor assembly mounted on the frame, the sheet material being fed to, supported by, and advancing with said conveyor assembly, the latter including longitudinally extending upper and lower endless, foraminous conveyors having adjacent, cooperating runs between which the sheet material is engaged, longitudi'nally spaced pairs of cooperating upper and lower, transversely extending pressurerolls mounted on the frame, said adjacent runs and the engaged sheet material passing between each pair of pressure rolls under compression, baffle means forming a longitudinal passage above the upper conveyor and a longitudinal passage below the lower conveyor, means to introduce a flow of heated air into said passages, means forming vertical passages extending from said longitudinal passages to adjacent corresponding runs between the pairs of pressure rolls, said vertical passages directing the air flow against yet terminating adjacent but short of said corresponding runs, the heated air flow escaping from said vertical passages at said runs and into side portions of the housing separate from said longitudinal passages, and means to exhaust the heated air flow from said side portions of the housing.

2. A kiln for preformed, continuously traveling, composite paper and wood veneer sheet material having freshly adhesively engaged laminations, comprising a housing, a longitudinal driven conveyor assembly mounted on the frame, the sheet material being fed to, supported by, and advancing with said conveyor assembly, the latter including longitudinally extending upper and lower endless, foraminous conveyors having adjacent, cooperating runs between which the sheet material is engaged, longitudinally spaced pairs of cooperating upper and lower, transversely extending pressure rolls mounted on the frame, said adjacent runs and the engaged sheet material passing between each pair of pressure rolls under compression, the frame including transversely spaced longitudinal guide rails on which the other runs of said conveyors travel, longitudinal upper and lower baffie plates extending from said rails to the housing to form separate upper and lower longitudinal passages therein, said longitudinal passages being defined at the bottom and top respectively by the adjacent other run of the related conveyor, transversely extending hoods mounted on the frame and covering corresponding pressure rolls between the runs of each conveyor, closure plates extending between the ends of adjacent hoods to form vertical passages between the longitudinal passages and said adjacent cooperating runs, the hoods and said closure plates terminating at their inner edges adjacent but short of said adjacent cooperating runs, means to feed heated air into said longitudinal passages for flow therefrom through the vertical passages to impinge against said adjacent, cooperating runs and the engaged sheet material, the air flow then escaping between said inner edges and adjacent cooperating runs into side portions of the housing separate from said longitudinal passages, and means to exhaust the heated air flow from said side portions of the housing.

3. A kiln for preformed, continuously traveling, composite paper and wood veneer sheet material having freshly adhesively engaged laminations, comprising a housing, a longitudinal driven conveyor in the housing, the sheet material being fed to, supported by, and advancing with said conveyor, means in the housing to subject the conveyor supported sheet material to compression, said conveyor including a foraminous run in engagement with the sheet material, means forming air confining and directing passages in the housing above and below the conveyor and terminating in open ends adjacent said conveyor, said passage-forming means including straightedged side members disposed at their termination closer to each other than the width of the material on the conveyor, and means to force heated air into said passages in the direction of the conveyor whereby the air will impinge the central portion of the opposed faces of the material and will then flow laterally and escape from the passages between the side members and the conveyor so as to also impinge against the side portions of the material before escaping.

4. A kiln for preformed, continuously traveling, composite paper and wood veneer sheet material having freshly adhesively engaged laminations, comprising a housing, a longitudinal driven conveyor in the housing, the sheet material being fed to, supported by, and advancing with said conveyor, the latter including cooperating longitudinal runs between which the sheet material is engaged, said runs being foraminous, longitudinally spaced pairs of upper and lower pressure rollers engaging said runs to exert pressure against the material therebetween, means journaling the rollers Within the housing, air confining passage means in the housing including passage members disposed between the pairs of rollers above and belowthe conveyor and terminating in open ends disposed adjacent the conveyor and allowing air to escape past the side edges of the conveyor, means to force heated air into the passage members in the direction of the conveyor, and exhaust passsage means in the housing at the sides thereof into which the escaping air discharges.

5. A kiln for preformed continuously traveling sheet material comprising a housing, a longitudinal driven conveyor assembly within the housing and including endless conveyors having adjacent runs between which the material is engaged, transverse pressure units acting on said adjacent runs of the conveyor, each unit comprising a pair of pressure rollers, a frame Within the housing, means journaling the rollers at their ends in connection with the frame, means to manually adjust the journaling means of one such roller to alter the pressing effect thereof, and normally closed doors in the sides of the housing in the horizontal plane of the adjusting means.

References Cited in the file of this patent UNITED STATES PATENTS 1,228,430 Hahn June 5, 1917 1,676,091 Kemp July 3, 1928 1,877,047 Piazza Sept. 13, 1932 1,885,505 Bell Nov. 1, 1932 2,029,081 Mottweiler I an. 28, 1936 2,268,986 Hess et al. Jan. 6, 1942 2,422,105 Lehrer June 10, 1947 2,425,660 Ware et al. Aug. 12, 1947 2,473,629 Andrews June 21, 1949 FOREIGN PATENTS 328,551 France May 4, 1903 10,588 Great Britain 1906 

